JPS62187548A - Horizontal continuous casting apparatus - Google Patents

Abstract

PURPOSE:To execute good continuous casting operation without any leakage by arranging slantable coils wound at gap near boundary of a tundish nozzle and mold with large inner diameter, and adjusting slant of the coils in accordance with detecting of contact position of molten metal, shrunk by electromagnetic force, with the mold. CONSTITUTION:The slantable (theta) coils 98, 99 wound are arranged at the gap near the boundary 17 of the nozzle qr of the tundish 1 and the mold 3 with large inner diameter. The molten metal 95, of which diameter is reduced by the electromagnetic force generated by AC current of the coils 98, 99, is brought into contact with the mold 3 through flowing lubricant 46 at the contacting start position 112, to execute horizontal continuous casting toward casting direction 45 without any sticking of solidified shell to the mold 3. The contacting position 112 with the molten metal is detected by the position detecting means 109 through thermocouples 108, and the coils 98, 99 are slanted at suitable angle theta, to compensate a gap of the contacting position 112 by gravity. Further, thickness of the shell is also adjusted by slanting the coil. Therefore, the leakage of the molten metal 95 is prevented and the solidified shell is developed uniformly without any sticking to the mold 3 and good horizontal continuous casting operation is executed.

Description

[Detailed description of the invention] The present invention relates to a horizontal continuous casting method and apparatus.

In conventional horizontal continuous casting equipment, the tundish nozzle and mold are fixed to each other in order to prevent molten metal from flowing out between the tundish nozzle made of refractory material and the water-cooled mold. was. Therefore, the portion of the tundish nozzle adjacent to the water-cooled mold is cooled, and a solidified shell is formed at the molten metal contact area, which is fixed to the tundish nozzle. In addition, since the molten metal enters the pores of the refractory material that makes up the tundish nozzle and solidifies as it is, the adhesion strength increases. Therefore, when the 1IjTL body was pulled out, the solidified shell was sometimes torn, resulting in so-called breakout.

In the prior art to solve this problem, a nonporous silicon nitride ring or boron nitride ring with excellent lubricity is hermetically connected between the tundish nozzle and the mold. These silicon nitride rings and boron nitride rings have a short lifespan and are expensive.

Moreover, even if these materials are used, although they have the effect of alleviating the sticking of the tundish nozzle and the solidified shell, it is not possible to completely avoid the sticking of the mold tube and the solidified shell. As a result, intermittent extraction is forced.

In order to solve these drawbacks of the prior art, an electromagnetic field generating means that generates a larger magnetic flux density at the bottom than at the top of the molten metal is arranged near the boundary between the tundish nozzle and the mold, and the molten metal is A horizontal continuous casting facility has been proposed in which constriction is performed near the boundary (Japanese Patent Application No. 56-94').
333). By squeezing the molten metal in this way, the molten metal will not come into contact with the tundish nozzle (
As mentioned above, the solidified shell is prevented from sticking to the tundish nozzle, and continuous extraction is possible. Furthermore, since the tundish nozzle and the mold do not have to be fixed together, it is possible to vibrate the mold, which also prevents the two-layer hard shell from sticking to the tundish nozzle and the mold.

However, since the amount of molten metal stored in the tundish changes, the static pressure acting on the surface layer of the molten metal in the tundish nozzle and the mold also changes. In particular, during unsteady situations such as when a dollar is exchanged at the end of casting, the liquid level of the molten metal in the tundish fluctuates greatly, and the static pressure of the molten metal in the tundish nozzle and mold fluctuates accordingly. . In such a case, the position where the molten metal formed by the electromagnetic field generating means comes into contact with the inner surface of the mold moves in response to fluctuations in static pressure. As the position of contact of the molten metal with the inner surface of the mold changes, the total length of the cooling zone within the mold changes. Since the solidified thickness changes accordingly, it becomes impossible to obtain a good slab. Furthermore, in the mold, the static pressure is greater at the lower part of the molten metal, so the contact pressure of the molten metal against the inner surface of the mold tends to be greater at the lower part, even with the electromagnetic field generating means. Therefore, the cooling effect of the lower part of the molten metal becomes large, making it impossible to obtain a good slab due to uneven cooling.
The same is true of the prior art in which an electromagnetic force is generated to apply a restriction to the molten metal from the tundish nozzle toward the center, as shown in FIG.

Another prior art is JP-A-53-761.30. In this prior art, in order to compensate for the gravity of the molten metal, an electrode is immersed in the molten metal in a tundish nozzle, and a longitudinal current is passed through the molten metal, perpendicular to and horizontal to the longitudinal direction of the slab. The structure is configured to compensate for the gravity of the slab by generating a magnetic field. In such prior art, the electrodes are immersed in the molten metal and a current is supplied to the molten metal, so maintenance thereof is troublesome.

An object of the present invention is to provide a horizontal continuous casting apparatus in which the thickness of the solidified shell produced on the surface layer of molten metal by cooling on the inner surface of the mold is uniform along the circumferential direction. .

The present invention is constructed by surrounding at least the vicinity of the boundary between a tundish nozzle and a mold having an inner diameter larger than the tundish nozzle, and winding the tundish nozzle at intervals in the radial direction. It is installed so that it can be angularly displaced around a horizontal axis perpendicular to the axis, and is excited by AC power to apply an electromagnetic force to the molten metal toward the center so that the diameter of the molten metal decreases near the boundary between the tundish nozzle and the mold. a coil to be actuated; a detection means for detecting the upper and lower contact start positions of the reduced diameter molten metal on the inner surface of the mold; and a drive for angularly displacing the coil around a horizontal axis perpendicular to the axis of the tundish and the mold. and, in response to the detection output of the detection means, when the contact start position is at the upper part and is downstream in the pulling direction than the lower part, the coil is positioned in such a position that the lower part of the coil is downstream in the pulling direction than the upper part of the coil. The present invention is a horizontal continuous casting apparatus characterized in that it includes a control means for controlling the amount of angular displacement of the coil by the drive means so that the lower part approaches the molten metal.

Further, the present invention is configured such that at least the vicinity of the boundary between the tundish nozzle and the mold having an inner diameter larger than that is surrounded and wound at intervals in the radial direction,
It is provided so that it can be angularly displaced around a horizontal axis perpendicular to the axis of the tundish nozzle and the mold, and is excited by AC power so that the molten metal is centered on the molten metal so that the diameter of the molten metal is reduced near the boundary between the tundish nozzle and the mold. a coil for applying an electromagnetic force in a direction; a detection means for detecting the thickness of the upper and lower solidified shells of the cast body at the mold exit; In response to the detection output of the driving means for displacing and the detection means, when the thickness of the solidified shell = 7- is greater at the lower part than at the upper part, the lower part of the coil is on the downstream side in the drawing direction than the upper part of the fill. control means for controlling the amount of angular displacement of the coil by the driving means so that the lower part of the coil approaches the molten metal at vf.
This is a horizontal continuous casting machine with a special feature.

According to the invention, the coil is arranged to be angularly displaceable about a horizontal axis perpendicular to the axes of the tundish nozzle and the mold so as to reduce the diameter of the molten metal at least near the boundary between the tundish nozzle and the mold. . The detection means detects the upper and lower contact start positions of the reduced diameter molten metal with the inner surface of the mold. Therefore, when the contact start position at the upper part is on the downstream side in the pulling direction than the lower part (backward in the pulling direction 45, that is, to the right in Figure 2, eISS diagram, and Figure 6), the lower part of the fill is displaced in two directions. do. As a result, a larger electromagnetic force acts on the lower part of the molten metal toward the center. Therefore, the contact start position where the molten metal contacts the inner surface of the mold can be adjusted to be approximately the same vertically, or so that the lower part of the molten metal is on the downstream side in the drawing direction than the upper part. Thereby, the thickness of the solidified shell of the cast body at the mold exit can be made approximately equal between the upper and lower parts.

It also detects the thickness of the upper and lower solidified shells of the Ill structure at the mold exit, and when the thickness of the solidified shell is larger at the bottom than at the top, the lower part of the coil is displaced upward, thereby causing the lower part of the molten metal to move toward the center. A larger electromagnetic force can be applied towards the solidified shell, increasing the thickness of the solidified shell
The upper and lower parts of the body can be made almost equal.

That is, the coil is provided so as to be angularly displaceable around a horizontal axis perpendicular to the axes of the tundish nozzle and the mold,
When the contact start position of the reduced diameter molten metal with the inner surface of the mold is at the upper part and is downstream of the lower part in the drawing direction, the lower part of the coil is positioned downstream of the upper part of the coil in the drawing direction (i.e.!@2 (with θ being an obtuse angle like the electromagnetic field generating means 99 shown in the figure), the lower part of the coil should be moved closer to the molten metal (that is, the angle θ in Fig. 2 should be further increased) (clockwise) the coil is driven by angular displacement! 11J will be given. Further, when the thickness of the solidified shell is greater at the lower part than at the upper part, the lower part of the coil is angularly displaced so as to approach the molten metal with the lower part of the coil being downstream in the drawing direction than the upper part of the coil. In this way, a larger electromagnetic force is applied to the lower part of the molten metal toward the center, and as described above, a high-quality corpse can be obtained.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is an overall system diagram showing the basic configuration of the present invention. In this horizontal continuous casting equipment, a tundish 1 is provided with a heating device 2 for stabilizing the temperature of the molten metal within the tundish 1. mold 3
The empty structure 4 is pulled out from the cooling zone 5 by a pulling device 6, and cut by a cutter 1ffi7 to obtain an ingot 9. This ingot 9 is conveyed by a roller table 1o.

FIG. 2 shows the basic structure of the present invention, and is an enlarged sectional view of the vicinity of the mold 3. Tanditshu 1 is fireproof material 1
1 is lined with molten metal 12. This tundish 1 is provided with a tundish nozzle 14 made of a refractory material. The mold 3 has a cooling fluid passage in which the copper mold tube is cooled, and the passage 16 for the cast body 4 of this mold 3 communicates coaxially with the tundish 7 nozzle 14.

The nozzle hole 95 of the tundish 1 is provided with a sliding date 96 for allowing and blocking the flow of the molten metal 12, and this sliding date 96 is driven by a driving sill 97. Near the end of the tundish nozzle 14 closer to the mold 3, an electromagnetic field generating means 98, which is a coil formed by winding a wire around the tundish nozzle 14, is arranged. Due to the electromagnetic force generated by the electromagnetic field generating means 98, the molten metal 12 flowing within the tundish nozzle 14 is radially inwardly curved.

The mold 3 has a larger inner diameter than the tundish nozzle 14. Near the end face of the mold 3 facing the tundish 7 nozzle 14 at the boundary 17 between the tundish 7 nozzle 14 and the mold 3, another electromagnetic field generating means 9 is provided.
9 is arranged in a plane inclined by an angle θ with respect to the drawing direction 45. The electromagnetic field generating means 98 and 99 may be integrated, or only one hand #5t99 may be angularly displaceable as described later, and an induced current absorbing plate 98 is provided inside them. ', 99' are provided.

FIG. 3 is a diagram showing the static pressure distribution acting on the surface layer of the molten metal 12 near the boundary 17. Static pressure acts on the surface layer of the molten metal 12, which increases toward the bottom. Therefore, as shown in the t54 diagram, the center position M10 of the molten metal 12 is
When the electromagnetic field generating means 98 having a shape almost symmetrical to the tune #1101 showing the static pressure distribution in FIG. 3 with respect to 0 is arranged, the distribution of the electromagnetic force becomes as shown in the tune #1103 in the tj44 diagram. That is, an inwardly concave electromagnetic force distribution is obtained on both sides of the molten metal 12. Such a curve 1゜3
If the static pressure shown in FIG. 3 is compensated for by the electromagnetic force given by , the diameter-reduced portion 22 becomes laterally expanded in diameter. Therefore, if the shape of the electromagnetic field generating means 98 is made to be slightly concave inward from both sides of the curve, the electromagnetic force distribution becomes a curve @104 shown by a broken line. This curve 104 is the third
It has a similar shape to the curve 101 showing the static pressure distribution in the figure, and by using the electromagnetic field generating means 98 having such a shape, the distance between the reduced diameter portion 22 and the inner surface of the tundish 7 nozzle 14 can be changed along the circumferential direction. It is possible to make it almost uniform.

The electromagnetic field generating means 99 is a coil whose strands are wound around the axis of the mold 3. When a current flows through the strands of the electromagnetic field generating means 99 perpendicular to the page of FIG. 2 and toward the back of the page, the molten metal i12 in the mold 3 has a current flowing toward the front of the page of FIG. Reference mark 105
An eddy current shown by is generated, and a magnetic field is generated in the direction of arrow 10G. Therefore, the molten metal 1 in the mold 3
2 has an arrow 107 pointing forward along the pulling direction 45.
An electromagnetic force shown by is generated. Shigamo electromagnetic field generating means 9
One is inclined at an angle θ with respect to the axis of the mold 3 so as to move toward the front in the drawing direction 45 as it goes downward. As a result, a larger electromagnetic force is applied to the molten metal 12 in the mold 3 in the lower part than in the second part. Therefore, the molten metal 12 within the mold 3 maintains a plane substantially perpendicular to the drawing direction 45.

Therefore, the solidification conditions at the position where the molten metal 12 contacts the inner surface of the mold 3 are uniform over the entire circumferential direction. In this way, the contact length of the molten metal 12 within the mold 3, that is, the cooling capacity, does not differ between the upper and lower positions, and a uniform cooling effect can be obtained.

In this embodiment as well, a position detecting means 109 comprising, for example, a plurality of thermocouples 108 is provided at any position along the circumferential direction of the mold tube 33 near the end of the mold 3 near the tundish nozzle 14.

Molten metal 1 detected by this position detection means 109
The electric power supplied to the electromagnetic field generating means 98 and 99 is controlled by a control means (not shown) so that the contact start position 112 of No. 2 is at a predetermined constant position. As a result, the contact start position 112 remains at a substantially constant position regardless of fluctuations in the static pressure acting on the surface layer of the molten metal 12 near the boundary 17, and a good slab can be obtained. Also, since the separation start position 113 is kept constant, the lubricant 4
The 6th and 7th holes 42 are not obstructed.

FIG. 5 is a front view of one embodiment of the present invention, FIG. 6 is a sectional view taken along the section line Vl--Vl in FIG. 5, and FIG.
The figure is a cross-sectional view taken along the section line ■--■ in FIG. 6. In this embodiment, the inclination angle θ of the nine electromagnetic field generating means in the configuration shown in FIGS. 12 contact start positions are maintained at the same set position over the entire circumference.

The electromagnetic field generating means 9, which are coils, are arranged such that the lower part thereof is downstream in the drawing direction 45 than the upper part.

The contact start position of the molten metal 12 with the inner surface of the mold tube is such that the upper and lower parts are at the same position in the axial direction, as described above, or the upper part is located at the same position in the drawing direction 45 as shown in FIG. 10, which will be described later. It must be on the upstream side.

For this purpose, when the contact start position is at the upper part and is downstream of the lower part in the drawing direction 45, the lower parts of the nine electromagnetic field generating means are driven to be angularly displaced so that they approach the molten metal, that is, the angle θ becomes larger. Ru.

As a result, the contact start position at the bottom of the molten metal can be moved downstream in the drawing direction 45, while the contact position at the top of the molten metal can be moved upstream in the drawing direction.

The electromagnetic field generating means 99 is housed in a storage box 116 made of a non-magnetic material filled with inert gas.
6 is fixedly provided in a cooling box 117 made of a non-magnetic material through which cooling water flows. A pair of trunnion shafts 118 and 119 are fixed to the outer periphery of the cooling box 117, extending in the horizontal direction and perpendicular to the axis of the tundish 7 nozzle 14. These trunnion shafts 118. ．． 119 are trunnion bearings 120 and 121 fixedly supported by the mold 3;
can be received by

Each trunnion shaft 118.1.39 is a hollow cylinder;
A cylinder 122 connected to the storage box 11G passes through one trunnion shaft 118 and projects outward. This cylinder 12
The outer end of the cylinder 1 is closed, and a tube 123 through which a cable for connecting to the electromagnetic field generating means 99 is inserted is inserted into the cylinder 1.
It protrudes concentrically through the outer end of 22. Pipe body 12
The power supply cable 12 is connected to the end of 3 via the rotary joint 124.
5 is connected. Further, a sealed gas supply hose 127 is connected to the outer end of the cylindrical body 122 via a rotary joint 126. Note that the supply pressure of the sealed gas is set higher than the pressure of the cooling water in the cooling box 117, so that even if the sealing of the storage box 116 is incomplete, the cooling water will not flow into the storage box 116. Accidents such as electrical leakage due to inflow are prevented as much as possible.

The inside of the cooling box 117 is partitioned by a partition plate 128 on the axis of the other trunnion shaft 119 .

A water supply pipe 129 and a drain pipe 130 are inserted into the trunnion shaft 119.
30 are respectively connected to the cooling box 117 on both sides of the partition plate 128. Also, water supply pipe 129 and drain pipe 1
The other end of 30 concentrically passes through trunnion shaft 119 and projects outward. A water supply hose 132 is connected to the other end of the water supply pipe 129 via a rotary joint 131, and a water supply hose 132 is connected to the other end of the water supply pipe 129.
A drain hose 1 is connected to the other end of the drain hose 30 via a rotary joint 133.
34 are connected. Therefore, the cooling water goes around the inside of the cooling box 117 almost once and is discharged.

The hydraulic sill 115 is fixed to the mold 3 near the other trunnion shaft 119 with an axis parallel to the mold 3. A drive lever 135 extending radially outward is fixed in the middle of the other trunnion shaft 11, and a screw 1 of the drive means 115 is attached to the outer end of the drive lever 135.
The tip of the connecting rod 136 is connected with a pin. Therefore, by driving the hydraulic cylinder 115 to expand and contract, the trunnion shafts 118 and 119 rotate about their axes, and the electromagnetic field generating means 99 swings as shown by arrow 137.

In this way, the angle θ that the electromagnetic field generating means 99 forms with the axis of the mold 3 can be arbitrarily adjusted.

Position detecting means 138 and 139 for detecting the contact start position of the molten metal are provided at the upper and lower parts of the end g1 of the mold tube 33 near the tundish 7 and the nozzle 14, respectively. These position detection means 138,1
39 is given to the control means 32 shown in Figure @8 described later,
The control means 32 controls the hydraulic sill 115 so that the contact start positions of the second and lower parts of the molten metal 12 are at the same preset position along the axis of the mold 3.

Figure t58 is a block diagram showing the configuration of the control means 32. The signals from the position detection means 138 and 139 are transmitted to the control means 3.
It is applied to a comparator 88 via arithmetic unit 87 of No. 2. Signals from the eight setters are input to the comparator 88 , and the comparator 88 provides a signal corresponding to the difference between the signal voltages from the arithmetic unit 87 and the setter 89 to the control unit 90 . Control unit 90
controls the hydraulic pressure supply means 68 in response to the signal from the comparator 88, whereby the hydraulic pressure 115 is strongly activated.

=19- By such a control means 32, the mold tube 33
The hydraulic sill 115 works so that the contact start position of the molten metal 12 with the inner surface of the upper and lower parts is the same position along the axial direction, but is also a preset position. As mentioned above, when the contact start position of 3.2 with the molten metal on the inner surface of the mold tube 33 is maintained at the same position set at the upper and lower parts, both sides of the molten metal 12 are also necessarily at the same position. becomes. Therefore, the molten metal 12 starts contacting the inner surface of the mold tube 33 at the same set position along the axial direction over the entire circumference of the inner surface of the mold tube 33. Thereby, the length of the cooling zone in the mold tube 33 becomes uniform over the entire circumference of the molten metal, and the solidified thickness becomes uniform over the entire circumference, so that a good slab can be obtained.

According to this embodiment, the inclination angle θ of the nine electromagnetic field generating means can be easily adjusted in response to fluctuations in static pressure. Furthermore, since it has a trunnion support structure, power supply and water supply and drainage can be carried out extremely easily. Moreover, since the heat generated by the electromagnetic field generating means 99 and the heat given to the electromagnetic field generating means 99 from the molten metal 12 are absorbed by the cooling water, the nine electromagnetic field generating means do not overheat. Furthermore, since the nine electromagnetic field generating means are supported on the mold 3 side,
It is convenient for receiving the reaction force from the molten metal 12. In addition, when the mold 3 is configured to vibrate, it is necessary to support the nine electromagnetic field generating means on a frame of the mold vibrating device.

FIG. 9 is a front view of another embodiment of the invention.

This embodiment is similar to the embodiments shown in FIGS. 5 to 7 described above, but it should be noted that the electromagnetic field generating means 99 is movable along the axis of the mold 3. That is, the trunnion bearings 120 and 121 are supported on the support cart 160, and the hydraulic sill 151 is also supported on the support cart 160.
Supported at 0.

Beneath the tundish nozzle 14 and the mold 3, there is a rail 16 extending parallel to the tundish nozzle 14.
1 has been laid, and the support cart 160 is connected to the rail 16.
1 can be moved freely. A hydraulic sill 162 having an axis parallel to the rail 161 is supported at a fixed position below the support base 11160.
The piston rod 163 of the piston rod 163 is coupled to the support carriage 160 via a pin. Therefore, by extending and contracting the hydraulic cylinder 162, the support stand 111160 is moved on the rail 161 between the stoppers 164 and 165 at both ends, and therefore the electromagnetic field generating means 99 is moved along the axis of the tundish nozzle 14.

In this embodiment, the electromagnetic field generating means 99 is moved in the drawing direction 45.
Since the contact point of the molten metal 12 can be changed, the cooling conditions can be changed.

As a further embodiment of the present invention, as shown in FIG.
It may be controlled to a more forward position along the pulling direction /I5. In this way, the quality of contact between the molten metal 12 and the mold tube 33 differs between the upper and lower parts, and the contact length at the lower part becomes smaller, but the contact pressure with the mold tube 33 at the lower part of the molten metal 12 is greater. Therefore, even if the contact length is relatively short, the cooling conditions are equal to the upper part, and therefore the solidification thickness can be made uniform over the entire circumference of the molten metal 12.

In other embodiments of the invention, the hydraulic cylinder 115 may be a pneumatic cylinder or a motor. Further, in each of the above-described embodiments, the tundish 7 has a loop 14.
Although the case where the axially perpendicular cross section of the mold 3 is rectangular has been shown, the axially perpendicular cross section of the tundish nozzle 14 and the mold 3 may be circular.

As another embodiment of the present invention, at the exit of the mold 3,
A solidification thickness gauge may be provided to measure the thickness of the solidified shell in the upper and lower surface layer portions of the molten metal 12. These solidification thickness gauges are shown in the tjSa diagram with the reference numerals 91.92,
These detected values are given to the comparator 88 via the arithmetic unit 93 of the control means 32, as shown in FIG. In this way, the thickness of the solidified shell at the exit of the mold 3 is fed back to the control of the drive means 31, allowing more precise control. Note that a radiant surface thermometer may be used instead of the solidification thickness gauge 91,92.

When the thickness of the solidified shell is larger at the bottom than at the top, the angle θ is displaced to become larger. Therefore, molten metal 1
A large electromagnetic force in the center direction acts on the lower part of the mold tube 33 of the molten metal pA12, and the contact start position can be moved downstream in the drawing direction.
The contact pressure with the inner surface can be reduced. In this way, the thickness of the solidified shell can be made equal in the upper and lower parts at the exit of the mold 3.

As described above, according to the present invention, the coil is angularly displaced so that the position where the molten metal starts contacting the mold or the cooling state of the molten metal at the exit of the mold is at a preset position or state. Compensation can now be reliably performed, cooling can always be achieved under stable cooling conditions regardless of fluctuations in the surface pressure acting on the surface layer of molten metal, and good slabs can be obtained. can. Further, since the position where the molten metal leaves the tundish nozzle is also held at the set position, the lubricant can be stably supplied.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram showing the basic configuration of the present invention;
FIG. 2 is an enlarged cross-sectional view of the vicinity of the mold 3 showing the basic configuration of the present invention, FIG. 3 is a diagram showing the surface pressure distribution acting on the surface layer of the molten metal 12 near the boundary 17 in FIG. 4 is a diagram showing the electromagnetic force distribution, FIG. FIG. 8 is a block diagram showing the configuration of the control means 32, and FIGS. 9 and 10 are simplified cross sections of other embodiments of the present invention. It is a diagram. 3... Mold, 12... Molten metal, 14... Tundish nozzle, 17... Boundary, 98.99...
- Electromagnetic field generating means, 112.16G, 167... Contact start position, 24... Solidified shell, 1.09, 138,
139... Position detection means, 32... Control means, 31
... Drive means, 45... Pulling direction, 115...
Hydraulic Schilling, 160...Support trolley

Claims (2)

[Claims] (1) It is constructed by surrounding at least the vicinity of the boundary between the tundish nozzle and a mold having a larger inner diameter, and being wound at intervals in the radial direction, perpendicular to the axis of the tundish nozzle and the mold. A coil that can be angularly displaced around a horizontal axis, is excited by AC power, and applies electromagnetic force toward the center of the molten metal so that the diameter of the molten metal decreases near the boundary between the tundish nozzle and the mold. a detection means for detecting the contact start positions of the reduced diameter molten metal on the inner surface of the mold in the upper and lower directions; and a driving means for angularly displacing the coil around a horizontal axis perpendicular to the axes of the tundish nozzle and the mold; In response to the detection output of the detection means, when the contact start position is at the upper part and is downstream in the pulling direction than the lower part, the lower part of the coil is melted with the lower part of the coil being downstream in the pulling direction than the upper part of the coil. 1. A horizontal continuous casting apparatus, comprising: control means for controlling the amount of angular displacement of the coil by the drive means so that it approaches the metal. (2) It is configured by surrounding at least the vicinity of the boundary between the tundish nozzle and a mold having a larger inner diameter, and being wound at intervals in the radial direction, and perpendicular to the axis of the tundish nozzle and the mold. A coil that can be angularly displaced around a horizontal axis, is excited by AC power, and applies electromagnetic force toward the center of the molten metal so that the diameter of the molten metal decreases near the boundary between the tundish nozzle and the mold. a detection means for detecting the thickness of the upper and lower solidified shells of the cast body at the mold exit; a drive means for angularly displacing the coil about a horizontal axis perpendicular to the axes of the tundish nozzle and the mold; In response to the detection output, when the thickness of the solidified shell is greater at the lower part than at the upper part, a driving means is configured to cause the lower part of the coil to approach the molten metal in a posture such that the lower part of the coil is downstream in the drawing direction than the upper part of the coil. a control means for controlling the angular displacement amount of the coil.